Re: Very High Load, kernel 2.4.18, apache/mysql

=?ISO-8859-2?Q?Pawe=B3?= Krawczyk (kravietz@aba.krakow.pl)
Wed, 25 Sep 2002 09:51:59 +0200


On Wed, Sep 25, 2002 at 12:20:26AM -0700, Simon Kirby wrote:

> Again, not locking, but fsync(). It's safe providing your machine never
> crashes. :) Of course, there's still a chance it can be corrupted
> _with_ fsync() anyway, but the difference is the clients will get a
> result beore it guarantees the data will be on disk.

Many Linux distributions configure syslog to use synchronous writes
for each logged line, which caused very high load on busy systems
I've seen.

Go through your /etc/syslog.conf and change every "/var/log/messages"
to "-/var/log/messages", the minus enables asynchronous writes.

Also try disabling logging for Apache at all for some time (set ErrorLog,
AccessLog or CustomLog to /dev/null) and see what happens.

-- 
Paweł Krawczyk, Kraków, Poland  http://echelon.pl/kravietz/
horses: http://kabardians.com/
crypto: http://ipsec.pl/
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